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FRANK LABORTORY OF NEUTRON PHYSICS
ION BEAM ANALYSIS
1. Diale Boitshoko Phenyo (UWC)
2. Sefage Amanda (UZ)
3. Nkosi Steven (CSIR)
Republic of South Africa
Supervisor: A.P. Kobzev (JINR, Dubna)JINR Summer Practice 2009
VAN DE GRAAFF ACCELERATOR EG-5
Main Characteristics
•Energy region 0.9-3.5 MeV
•Energy spread less than 500eV
•Beam intensity 10µA for He and
30µA for H.
Types of ions used
•4He+ and H+
JINR Summer Practice 2009
ACCELERATOR EG-5
JINR Summer Practice 2009
ANALYTICAL METHODS
• Rutherford Backscattering Spectrometry (RBS)
• Elastic Recoil Detection Analysis (ERDA)
• Particle Induced X-ray Emission (PIXE)
JINR Summer Practice 2009
2
12
12
12
122
0
12
cos)sin(
MM
MMM
E
Em
PRINCIPLE OF RBSKINEMATIC FACTOR
Atomic mass of target. ZJINR Summer Practice 2009
2122
12
24
2
22
2122
12
222
21
)sin(sin
)]cos)sin[(4)
4(),(
MMM
MMM
E
eZZER
SCATTERING CROSS SECTION
Z1 - Atomic number of incident particle
Z2 - atomic number of target
M1 – Atomic mass of incident particle
M2 – Atomic mass of target
Ѳ - Scattering angle
JINR Summer Practice 2009
PRINCIPLE OF RBS
1
x+
θ1ΔX
θθ2
ΩDetector
outinm EEEKE )( 021
E0, Z1, M1
E1, Z2, M2
21смэВ
dx
dE
N
Stopping cross section
N-Number of particles in the layer
dx
dE -Energy loss per unit length
JINR Summer Practice 2009
RBS EXPERIMENTAL RESULTS
A = σΩ .Q . Nt
A – total number of detected particlesQ – total no. of inc. ParticlesNt – no. of target atoms per unit area
Layer Element Conc. (at.%)
1 Niobium 100
2
Titanium 79Oxygen 21
3 Silicon 100
JINR Summer Practice 2009
Channel number
Layer Element Thickness (nm)
1 Titanium 418
2 Niobium 254
3 Silicon 2 mm
RBS EXPERIMENTAL RESULTS
Channel number
JINR Summer Practice 2009
RBS EXPERIMENTAL RESULTS
JINR Summer Practice 2009
200 400 600 800 1000 12000
500
1000
1500
2000
2500
3000
3500
4000
Yie
ld S
c.
Channel number
CO
TiSi
Si-Substrate
Energy = 2.01 MeV, H+ Detector Layer Element Conc.at% Thickness (nm)
1 Titanium 80Carbon 10 180Oxygen 10
2 Titanium 4042.3Silicon 50
Oxygen 103 Silicon 100 2 mm
PRINCIPLE OF ELASTIC RECOIL DETECTION ANALYSIS
JINR Summer Practice 2009
ERDA-RESULTS
200 400 600 800 1000 12000
500
1000
1500
2000
2500
3000
3500
4000
Bac
kSca
tterin
g In
ters
ity
Channel number
experimental simulated
Silicon
Carbon
Energy = 2.297 MeV, 4He+
Detector = 135
Thickness = 2600E+15 at./cm2
Element Conc. (%)
H ydrogen 35
C arbon 35
Silicon 30
Cou
nts
JINR Summer Practice 2009
ERDA – RESULTS cont,d
Element Conc. (%)
H ydrogen 26
C arbon 60
O xygen 14
Channel number
Channel number
Thickness = 1570E+15 at./cm2
JINR Summer Practice 2009
PRINCIPLE OF PIXE
Characteristics X-rays
JINR Summer Practice 2009
PRINCIPLE OF PIXE
Characteristics X-rays
JINR Summer Practice 2009
PRINCIPLE OF PIXE
Moseley law
• Rc – Rydberg’s constant• Z – atomic number• Sn – screening constant• n – main quantum number• ν - frequency of X-ray
quantum
JINR Summer Practice 2009
200 400 600 800 1000 1200 1400 16000
10
20
30
40
50
60
70
80
90
26.35
16.8420.12
17.7513.94
11.893.35
Inte
nsi
ty
Channel number
CALIBRATION
JINR Summer Practice 2009
AEROSOL ANALYSIS BY PIXE & RBS
JINR Summer Practice 2009
550 600 650 700 750 8000
500
1000
1500
2000
2500
3000
3500
4000
Bac
ksca
tteri
ng
yiel
d
Channel number
Aerosol E
p=2.005 MeV
=1350
S
Na AlSi
CaFe
F
O
NC
AEROSOL ANALYSIS BY PIXE & RBS
JINR Summer Practice 2009
Element Concen. At. % Method Element Concen. At. % Method
C 41
RBS K 0.1 PIXE
N 20.5 RBS Ca 0.53 RBS
O 28 RBS Mn 0.007 PIXE
F 2.6 RBS Fe 0.14 RBS
Na 2.5 RBS Cu 0.002 PIXE
Mg 1.3 RBS Zn 0.01 PIXE
Al 1.3 RBS As 0.001 PIXE
Si 1.8 PIXE Sr 0.0006 PIXE
S 0.2 RBS Zr 0.005 PIXE
Cl 0.01 PIXE Ba 0.01 PIXE
AEROSOL ANALYSIS BY PIXE & RBS
JINR Summer Practice 2009
CONCLUSION
• Non-destructive methods ( Different fields i.e. Electronic devices , Multi layer-
structures, geologist, archaelogist etc)
• Determine structure and composition of materials
• Elemental analysis
• Elemental concentration, depth profile in thin films ( < 1 at.%)
JINR Summer Practice 2009
ELEMENT Ti Nb
MINIMUM THICKNESS, nm
30 10
MAXIMUM THICKNESS, nm
1800 1500
REAL THICKNESS, nm
264 169,5
SENSITIVITY, at/cm2 2x10xx16 1x10xx16
CONCLUSION cont.d
JINR Summer Practice 2009
Siyabonga
JINR Summer Practice 2009